Powerman5K Posted August 25, 2022 Share Posted August 25, 2022 I just replaced all my instrument cluster lights with LED's. I am able to get them all working but the E-Brake light. I have tried reversing the bulb polarity but it is still not lighting up when the E-brake is engaged. Where is my next point to check? Is there a fuse to it that could be blown? Sensor on the pedal/arm? Link to comment Share on other sites More sharing options...
ratdude747 Posted August 25, 2022 Share Posted August 25, 2022 Probably a corroded switch or disconnected wire. It'd be on the pedal assembly... shorts to ground. It also goes to a switch on your proportioning valve. Link to comment Share on other sites More sharing options...
Powerman5K Posted August 27, 2022 Author Share Posted August 27, 2022 Probably a corroded switch or disconnected wire. It'd be on the pedal assembly... shorts to ground. It also goes to a switch on your proportioning valve. Thanks! I'll look into this this weekend. Link to comment Share on other sites More sharing options...
Powerman5K Posted August 27, 2022 Author Share Posted August 27, 2022 Probably a corroded switch or disconnected wire. It'd be on the pedal assembly... shorts to ground. It also goes to a switch on your proportioning valve. Alright, I'm digging into this parking brake issue this weekend and here is where I'm at. I was able locate/spray the connection on the proportioning valve with contact cleaner. Now when I start the truck, the parking brake light comes on for a couple seconds then shuts off. Where is my next move? Does the connection look OK? I can't find a ground wire to the frame anywhere. Nor can I find any type of wiring or switch on the parking brake pedal assembly. Link to comment Share on other sites More sharing options...
FuzzFace2 Posted August 27, 2022 Share Posted August 27, 2022 Alright, I'm digging into this parking brake issue this weekend and here is where I'm at. I was able locate/spray the connection on the proportioning valve with contact cleaner. Now when I start the truck, the parking brake light comes on for a couple seconds then shuts off. Where is my next move? Does the connection look OK? I can't find a ground wire to the frame anywhere. Nor can I find any type of wiring or switch on the parking brake pedal assembly. Well that is not the Ebrake switch but a low PSI of the normal brake system. If there is a leak, broken brake line, a valve moves inside that brass part and turns on the dash light telling something is wrong ......... like the brake pedal going almost to the floor was not a clue! Now to see if the light works when you first turn on the key the dash lights should lite up if good as a test of the bulbs. Same for the fasten seat belt light. I think you can short the 2 wires and it should turn on the dash light / wiring. Mine only has 1 wire and I go to ground to test the light / wiring. The Ebrake did not have a light on the early 80's at least not my 81's Dave ---- Link to comment Share on other sites More sharing options...
Dyn Blin Posted August 28, 2022 Share Posted August 28, 2022 Well that is not the Ebrake switch but a low PSI of the normal brake system. If there is a leak, broken brake line, a valve moves inside that brass part and turns on the dash light telling something is wrong ......... like the brake pedal going almost to the floor was not a clue! Now to see if the light works when you first turn on the key the dash lights should lite up if good as a test of the bulbs. Same for the fasten seat belt light. I think you can short the 2 wires and it should turn on the dash light / wiring. Mine only has 1 wire and I go to ground to test the light / wiring. The Ebrake did not have a light on the early 80's at least not my 81's Dave ---- Dave is correct. 80, 81 82 & most 83 did not have the switch on the e-brake and wiring to light the dash indicator. Link to comment Share on other sites More sharing options...
Rusty_S85 Posted August 28, 2022 Share Posted August 28, 2022 Well that is not the Ebrake switch but a low PSI of the normal brake system. If there is a leak, broken brake line, a valve moves inside that brass part and turns on the dash light telling something is wrong ......... like the brake pedal going almost to the floor was not a clue! Now to see if the light works when you first turn on the key the dash lights should lite up if good as a test of the bulbs. Same for the fasten seat belt light. I think you can short the 2 wires and it should turn on the dash light / wiring. Mine only has 1 wire and I go to ground to test the light / wiring. The Ebrake did not have a light on the early 80's at least not my 81's Dave ---- With a properly functional proportionating valve your pedal shouldnt go to the floor with a brake failure. The purpose of the valve is when one circuit ie front or rear develops a leak the valve will be forced to the side with less pressure cutting the fluid off to the rest of the system and maintaining proper pedal pressure on the master cylinder side. If your valve is not functioning correctly then you would have a pedal going towards the floor as that circuit is not building pressure but is simply dumping the pressure through the leak. It is a big reason why I am hunting down for a NOS unit to replace mine on my truck as there is no way to test them if they are functioning properly or not plus I tried to take the switch out on mine to replace it with a new one I think the switch is bad as my dash light doesnt light up either but the switch broke off in the valve and if I pull it off the truck to try and get the broken plastic out I might as well just replace it. As far as the lighting up with the key on I dont believe mine does, only one that lights up while the buzzer is going when the key turns on is the fasten seat belt light. I honestly dont believe I ever seen a brake light on our year model trucks light up as a test with the key turned on. I dont think it even does it on my '78 Mercury either. Link to comment Share on other sites More sharing options...
Gary Lewis Posted August 28, 2022 Share Posted August 28, 2022 Well that is not the Ebrake switch but a low PSI of the normal brake system. If there is a leak, broken brake line, a valve moves inside that brass part and turns on the dash light telling something is wrong ......... like the brake pedal going almost to the floor was not a clue! Now to see if the light works when you first turn on the key the dash lights should lite up if good as a test of the bulbs. Same for the fasten seat belt light. I think you can short the 2 wires and it should turn on the dash light / wiring. Mine only has 1 wire and I go to ground to test the light / wiring. The Ebrake did not have a light on the early 80's at least not my 81's Dave ---- With a properly functional proportionating valve your pedal shouldnt go to the floor with a brake failure. The purpose of the valve is when one circuit ie front or rear develops a leak the valve will be forced to the side with less pressure cutting the fluid off to the rest of the system and maintaining proper pedal pressure on the master cylinder side. If your valve is not functioning correctly then you would have a pedal going towards the floor as that circuit is not building pressure but is simply dumping the pressure through the leak. It is a big reason why I am hunting down for a NOS unit to replace mine on my truck as there is no way to test them if they are functioning properly or not plus I tried to take the switch out on mine to replace it with a new one I think the switch is bad as my dash light doesnt light up either but the switch broke off in the valve and if I pull it off the truck to try and get the broken plastic out I might as well just replace it. As far as the lighting up with the key on I dont believe mine does, only one that lights up while the buzzer is going when the key turns on is the fasten seat belt light. I honestly dont believe I ever seen a brake light on our year model trucks light up as a test with the key turned on. I dont think it even does it on my '78 Mercury either. I don't remember when the park brake switch was added, but I think it was '84. Prior to that there was no indication that it was on so you wanted to put it ON so the truck not moving was the clue. As for indication that the bulb is working, that comes as you turn the key to Start. You can see that in the schematic below from the '85 EVTM, and that function was in all years. Link to comment Share on other sites More sharing options...
Powerman5K Posted August 28, 2022 Author Share Posted August 28, 2022 Well that is not the Ebrake switch but a low PSI of the normal brake system. If there is a leak, broken brake line, a valve moves inside that brass part and turns on the dash light telling something is wrong ......... like the brake pedal going almost to the floor was not a clue! Now to see if the light works when you first turn on the key the dash lights should lite up if good as a test of the bulbs. Same for the fasten seat belt light. I think you can short the 2 wires and it should turn on the dash light / wiring. Mine only has 1 wire and I go to ground to test the light / wiring. The Ebrake did not have a light on the early 80's at least not my 81's Dave ---- With a properly functional proportionating valve your pedal shouldnt go to the floor with a brake failure. The purpose of the valve is when one circuit ie front or rear develops a leak the valve will be forced to the side with less pressure cutting the fluid off to the rest of the system and maintaining proper pedal pressure on the master cylinder side. If your valve is not functioning correctly then you would have a pedal going towards the floor as that circuit is not building pressure but is simply dumping the pressure through the leak. It is a big reason why I am hunting down for a NOS unit to replace mine on my truck as there is no way to test them if they are functioning properly or not plus I tried to take the switch out on mine to replace it with a new one I think the switch is bad as my dash light doesnt light up either but the switch broke off in the valve and if I pull it off the truck to try and get the broken plastic out I might as well just replace it. As far as the lighting up with the key on I dont believe mine does, only one that lights up while the buzzer is going when the key turns on is the fasten seat belt light. I honestly dont believe I ever seen a brake light on our year model trucks light up as a test with the key turned on. I dont think it even does it on my '78 Mercury either. Ok. Sounds like mine is functioning properly then. It turns on with the key but then goes out. I have never had a buzzer with the key. Should I? Where do I chase that down? Link to comment Share on other sites More sharing options...
Gary Lewis Posted August 28, 2022 Share Posted August 28, 2022 Ok. Sounds like mine is functioning properly then. It turns on with the key but then goes out. I have never had a buzzer with the key. Should I? Where do I chase that down? Buzzers changed by the year, and as they were added ones like headlights-on were an option. In '81, which is the closest EVTM I have on the site to your '80 truck, the only buzzer was for the seatbelt. So I think that's the only one your truck should have. Link to comment Share on other sites More sharing options...
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